Cylinder lubrication



June 14, 1927.

R. w. DAVENPORT CYLINDER LUBRicATIoN Filed sept. r25, 1925 Patented June 14, 1927.

UNITED STATES PATENT oFFlc-Egf RANSOM W. DAVENPORT, OF DETROIT, MICHIGAN, ASSIGNOR T0 CHICAGO PNEUMTIC TOOL- COMFANY, NEW YORK, N. Y., A CORPORATION'OF NEWJERSEY.

CYLINDER LUBRICATION.

Application filed September 25, 1925. Serial No. 58,559.

rl `his invention relates to the lubrication of rubbing surfaces of moving parts With particular reference to the cylinders of engines, pumps, compressors and the like having reciprocating pistons. In one aspect the invention has particular application to Inechanically operated refrigerating systems and to the use of the liquid refrigerant as a lubricant for the pump or compressor.

In machines of the type described theusual method of lubricating the cylinder walls is by the splashing of lubricant thereon by the crank shaft. With this method it is not possible to control either the amount or the quality of the lubrication. With poorly litting rings on the piston and particularly after wear has developed, a condition known as oil pumping obtains resulting from the excessive amount of lubricant thrown on the cylinder walls, some of which makes its way past the piston into the working chamber of the machine. Such a condition is always objectionable and particularly so in refrigerating systems Where mixing oflubricant with the refrigerant is usually very undesirable..

Moreover, in the splash system the lubricant quickly becomes diluted through con.- densation and becomes contaminated with grit, carbon, bits of metal, etc., so that its lubricating qualities are impaired.

Among the objects of the present invention are to prevent excessive lubrication and oil pumping in machines of the type described, to insure adequate and constant lubrication of the cylinder Walls, to provide for the feeding of fresh lubricant thereto in regulated amount, to provide improved means for utilizing the liquid refrigerant in mechanical refrigerating systems for lubricating purposes, and in general' to improve prior lubricating arrangements in the interests of more satisfactory and efficient service. s

In order to illustrate the invention concrete embodiments thereof are shown in the accompanying drawing, in which:

Fig. l is a vertical, transverse sectional `:fievv through an internal combustion engine;

Fig. 2 is a diagrammatic illustration of a refrigerating system embodying the present invention and utilizing liquid refrigerant as the lubricant for the compressor, certain parts including the compressor being shown in section, and

Fig. 3 is a sectional View substantially on reciprocates a piston 5 through the action of connecting rod 6 actuated by crank 7 The inner Wall of the cylinder has an annular groove 8 therein disposed Within the range of movement of the piston 5. Lubricant is fed to the groove 8 through pipe 9 from an oil chamber or reservoir 10 which may have any suitable or well known manual control,

means 11 for regulating the flow of lubricant. By preference groove 8 has disposed therein suitable-packing material 12 of an absorbent or "fibrous nature which maybe generally circular in cross section and project beyond the groovefor rubbing contact with `the piston 5. The character of the packing and the manner of its disposition within the groove Will be clear from Figs. 2 and `3 which illustrate a cylinder on a larger scale. When the improved cylinder packing arrangement herein disclosed is used in a machine arranged for splash lubrication the groove 8, particularly when filled with a cord packing prevents access of an excessive amount of oil to the parts adjacent the working chamber of the invention but provides adequate lubrication through rubbing contact with the piston wall while eliminating all tendency to oil pumping. YVhile the chamber l() may be omitted since anv adequate amount of lubricant will reach groove 8 from the splash in the crank case, its use is preferred since it keeps packing cord 12 saturated with fresh lubricant and this assists the packing in repelling the diluted and vitiatcd lubricant in the crank case.

Fig. 2 illustrates diagrammatically an important adaptation of the invention to m'echanically operated refrigerating systems of the conventional compressorcondenserevaporator type or of the improved type disclosed in my copending application No. 708,936 filed April 25, 1924. This adapta- --tion enables liquid refrigerant, such for example as sulphur dioxide, to be used for compressor lubrication and thereby avoid the undesirable and sometimesinjurious effects produced when the lubricant in the compressor makes its way into the refrigerating system. The system illustrated in Fig.

outlet valve 20 into condenser 21 whence the refrigerant passes through a throttling device 22 into the vaporizer 17, t-lius completing the refrigerating cycle. The compressor cylinder 16 is formed with an annular groove 23 similar tothe one shown in Fig. 1, within which groove is "seated a corded packing 24. `A chamber 25 in the line between condensei' 21 and throttle device 22 serves to trap the liquid refrigerant or condensatel r which is conveyed by capillary attraction to the packing 24 in groove 23 by wicking 26 disposed in a conduit or pipe 27.

From the above it will be apparent that the present invention provides means for controlling both the quantity and the quality of fluid for the lubrication of cylinders of machines having reciprocating pistons, that when utilized in conjunction with a splash system oil pumping and the access of impurities in the lubricant to the rubbing surfaces are prevented, and that the invention has special application to the solution of the problem of lubrication of compressors in mechanically operated `refrigerating systems.

I claim as my invention:

1. In a mechanically operated refrigerating system of the c losed cycle type, a compressor for circulating the refrigerant, said compressor having a recess in the inner wall of the cylinder thereof, absorbent material in said recess, means for condensing the circulated refrigerant at one point in said system, a receptacle for the condensate, and means for conducting condensate from said receptacle to said recess to moisten said absorbent material.

2. In aI mechanically operated refrigerating system of the closed cycle type, a compressor for circulating the refrigerant, said compressor having a recess in the inner wall of the cylinder thereof, absorbent material in said recess, means for condensing the circulated refrigerant at one point in said system, a receptacle for the condensate, and a conduit with wicking therein extending from said receptacle to said recess to feed condensate by capillary attraction to said absorbent material.

3. In a mechanically operated refrigerat- .ing systemof the compressor-condenser-vaporizer type, a compressor having a cylinder and a piston reciprocable therein, said cylinder having a groove in the inner wall thereof, a condenser, and means for feeding liquid from said condenser into said'groove to lubricate the compressor.

4. In a' mechanically operated refrigeratiiig system of the conipressor-condenser-vapoi'izer type, a compressor having a cylinder and a piston reciprocable therein, said cylinder having an annular groove in lthe inner wall thereof so disposed as to be always covered by said piston, fibrous material in said groove projecting therebeyond, a condenser, and means for feeding condensate from said condenser to said groove to lubricate the compressor. l

5.. In a mechanically operated refrigerating system of the compressor-condenser-vaporizer type, a compressor having a cylinder and a piston reciprocable therein, said cylinder having a groove in the inner wall thereof so disposed as to be always covered by said piston, corded fibrous material in said groove, a condenser, means for trapping condensed refrigerant, and means for conducting the condensed refrigerant to said groove.

6. In a'. mechanically operated refrigerating system of the compressor-coiidenser-vaporizer type, a compressor having a cylinder and a piston reciprocable therein, said cylinder having a groove in the inner wall thereof so disposed as to be alwa'ys covered by said piston, corded fibrous material in said groove, a condenser, a vessel into which said condenser discharges to serve as a trap for condensed refrigerant, and a conduit for conducting tlie condensed refrigerant to said groove.

7. In a mechanically operated refrigerating system of the compressor-condenser-vapoiizer type, a compressor having a cylinder and al piston reciprocable therein, said cylinder having a groove in the inner wall thereof so disposed as to be always covered by said piston, corded packing in said groove engaging said piston, a condenser, a vessel into which said condenser discharges to serve as a trap for condensed refrigerant, and means conducting said refrigerant by capillary attraction to said packing comprising a conduit with wicking therein extending from said vessel to said compressor cylinder.

Signed by me at Detroit, l/Vayne County, 

